Interestingly, in a recent study using single-cell sequencing of multiple sclerosis WML material, C1QB has been identified as a marker for ‘microglia inflamed in multiple sclerosis’.50 The increased expression of C1QB in demyelinated white matter and lowered expression in demyelinated grey matter observed in this study may imply that the classical inflamed microglial signature may not be present in the demyelinated grey matter. This evidence concerns the gene C1QB and multiple sclerosis.